The present invention relates to linear motors and, more particularly, to cooling systems for removing heat from wound armatures of linear motors.
In my prior U.S. Pat. No. 4,560,911, I disclose a linear motor having a laminated slotted stator in the slots of which armature windings are wound. The motor employs a permanent magnetic field member facing the armature for producing linear force or motion of a movable member which may be either the armature or the field member.
The ultimate limit on the amount of force or work obtainable from a linear motor, in common with other motor types, is imposed by resistive heating in the armature windings. In my prior patent application, Serial No. 638,488, now U.S. patent Ser. No. 4,625,132 I employ a U-shaped motor casing enclosing the armature and field member. A seal closing the opening of the U-shaped frame permits the entire motor frame to be used as a duct for a cooling fluid, such as air. The air passes along the duct until released in the vicinity of the movable member. When used in a linear motor wherein only the armature coils in the vicinity of the movable member are energized, this device is very effective in directing the cooling air to the area it is needed.
I disclose liquid cooling systems in my U.S. patent application Ser. No. 887,383, now matured into U.S. Pat. No. 4,749,921, and U.S. patent application Ser. No. 859,915, now abandoned. In the above referenced patent, I employ a ladder or serpentine cooling coil disposed in the slots to remove heat from the armature iron. In Ser. No. 859,915, I disclose a non-magnetic armature with molded-in cooling coils.